DOCUMENT RESUME SE 016 635 AUTHOR TITLE ... connecIions for each type circuit. 28. Identify what...

DOCUMENT RESUME

ED 080 370 SE 016 635

AUTHOR Christensen, Larry; Lane, RobertTITLE General Science [Sahuarita High School Career

Curriculum Project.]INSTITUTION Sahuarita High School District 130, Ariz.PUB DATE [73]NOTE 75p.

EDRS PRICE MF -$0.65 HC-$3.29DESCRIPTORS Curriculum; *Curriculum Guides; *General Science;

Instructional Materials; Physics; Science Activities;Science Education; *Science Units; *Secondary SchoolScience; *Teacher Developed Materials

ABSTRACTThis unit entitled *General Science* is one of a

series of instructional guides prepared by teachers for the- SahuaritaHigh School (Arizona) Career Curriculum Project. The package issubtitled *Physical Science in General Science* and consists ofsections dealing with mechadics, electricity and light. A list of 41behavioral objectives is stated which covers all aspects of the unit.The section on mechanics is divided into nine problems dealing withterminology, forces and motion, ideal mechanical advantage, vectors,levers, pulleys, and the inclined plane._Each topic includes astatement of the rationale, objectives, information sources,activities and post-evaluation. The section on electricity deals withsix problem areas, and tie sek.tion on light consists of eight._Theseproblems are approached with a statement of the rationale or anoverview, followed by a series of student activities._ For relatedits in this series see SE 016 636 through SE 016 644,(7R)

O1%-tirsO00

L.11

FILMED FROM BEST AVAILABLE COPY

SAMARITA FIGH SCHOOL

CAREER

r-U RR ICULUM

PROJECT

COURSE T 1 TLE GENERAL SCIENCE

PACKAGE TITLE: MEC MAN ICS

BY

LARRY CHRI STENSEN & ROBERT LANE

U S DEPARTMENT OF HEALTHEDUCATION A WELFARENATIONAL INSTITUTE OF

EDUCATIONTHIS DOCUMENT HAS BEEN REPRODUCED EXACTLY AS RECEIVED FROMTHE PERSON OR ORGANIZATION ORIGINATING IT POINTS OF VIEW OR OPINIONSSTATED DO NOT NECESSARILY_ REPRESENT OFFICIAL NATIONAL INSTITUTE OFEDUCATION POSITION OR POLICY

GENERAL SCIENCE

OBJECTIVES

1. You will be able to define from memory 9 of 10 of the followingterms: fulcrum, ideal mechanical advantage, force, a newton (nt), work,rector, friction, lever, pulley, inclined plane.

2. You will be able to state from memory Newton's three laws of motionwith no mistakes.

3. You will be able to distinguish between speed and velocity.

4. Given the mess of an object and its acceleration, you will be ableto calculate the force exerted between two bodies.

5. You will be able to calculate the ideal mechanical Advantage (IMA)of some simple machines.

6. You will be able to determine the force and direction of theresultant of 2 forces acting on a body by a graphical method.

7. You will be able to calculate the IMA of a 1st Class l.ier and listat least 5 examples of a 1st class lever.

S. Given a resistance and applied effort you will be able to designand build a 1st class lever that would do the job. .

9. You will be able to calculate the IMA of a 2nd class lever and giveat least 5 seapples of a 2nd class lever.

10. Given a resistance and applied effort you will be able to designand build a'aid class lever to do the job.

11. You will be able to list the job opportunities and requirements fora career in the field of transportation.

12. You will be able to list from memory 5 examples of a 3rd class lever.

13. Given a resistance and applied effort you will be able to designand build a 3rd class lever to do the job.

14. Given any pulley system, you will be able to calculate the IMA ofa pulley system.

15. Given a resistance and an applied effort you will be able to designand build a pulley system to do the job.

You will be able to calculate the IMA of any inclined plane.

17. Given a resistance and an app110d effort you will be able todesign and construct an inclined plane to d- the job.

18. Demonstrate in five ways how electrons react with otner electrons,atoms, ions, and molecules.

19. Aemonstrate how to use a galvanometer.

21. State a rule few the strength of magnetic field around a coil.

21. Demonstrate the voltaic pile.

22. Demonstrate the measurement of electrical potential (voltage) ofvarious objects with a voltemeter.

23. Demonstrate the measuremnt of current (amperage) in an electricalcircuit with an ammeter.

24. Explore skins and knowledge that are useful at home in working withelectricity.

25. Explore some occupations in which electrical knowledge is necessary.

26. State Ohm's Law and discuss applications in your home and school.

27. State the uses of series and parallel circuits and demonstrate theproper connecIions for each type circuit.

28. Identify what light is and determine several ways it may be produced.

29. Identify or demonstrate certain properties of light such as illumination,

travel, and intensity.

31. Demonstrate light travel, illumination, and image by use of a pin-

hole camera.

31. Demonstrate that light travels in a straight line.

32. Identify units suchg! as candles, lumen, and inverse proportion.

33. Denionstaate a standard measure of illumination by actual experimentation.

34. Demonstrate what happens when light hits various types of surfaces.

35. Define and demonstrate:the "Law of Mirrors."

36. Demonstrate what happens to light when it passes thru van..interfaces such as water-air, glass-air, and air-glass.

37. Identify the index of refraction for various substances such as glass,ice, diamond, and water and describe -what this index might be used for.

38. To identify various uses of light, lenses, and mirrors for home,scientific, and industrial uses.

39. Identify the type of lens and demonstrate the arrangement Strlenma*used to form a microscope.

40. Identify the type of lens and demonstrate the arrangement of lensesused to fora a refracting telescope.

41. Identify the type of-lens and demonstrate the arrangement of lensesused be form a lens system for a box camera as well as a common 35 mm lenssystem.

1. Career ClusterA. HealthB. Agri-business and Natural ResourcesC. EnvironmentD. Public Servise

2. Specific Career AreasA. Health Services and researchB. Petroleum and related ProductsC. Production aroma of AgricultureD. Research and production areas of Natural ResourcesE. Pollution control in EnvironmentF. Extension programs in education

3. * Copy specific behavioral objectives from those listed in the unit.

Mechanics

introduction

The dictionary defines a machine as "Any device cc,nsist-

ing of 2 or more parts, which may serve to transmi--. and modify

force nd motion so as to di socle-desired kind of work."

There are many complex and sophisticated machines all

around us yet all can be reduced to 4 basic elements. These

basic elements have been .town to man for over 2000 years.

They are the lever, the pulp he wheel and axle and the

inclined plane. In the following problems you will investi-

gate each of these elements and some of their uses.

Problem i

Mechanics Terminology

Rationale:

L this problem you w,11 learn the terms that will be

necessary in order that we can communicate intelligently

about machines.

You all know what lott_K Is, right? It's what makes you

tired. A physicist has a more precise definition. He would

say that if you lifted for 10 minutes on a 1 ton block but

did not move it you have done NO work. So what is work?

Objectives:

1. You will be able to define from memory 9 of 10 of thefollowing terms:

1. fulcrum2. Ideal Mechanical Advantage iIMA)3. force4. a newton int)5. work6. rector7. friction8. lever9. pulley

10. inclined plane

Information Sources:

1. Comptons Illustrated Science Dictionary

2. Glossary Modern Science 3

Almost any other dictionary.

2

Activities:

1. Look up and write down the de initIons for the wordslisted in Objective 1. Check your definitions withyour instructor lifore taking the evaluation _

Post-Evaluation:...

Write from memory the definitions listed in Objective 1.

Problem 2

Mechanics - Forces and notion

Rationale:

In order that you may study simple mechanics yOU

must first have some concept of force and motion. Every

particle of matter in the universe is continually experi-

encing forces of one kind or another. One example is the

force of gravity. Gravity is the force that gives each of

us our weight. If you w:11 recall in the 1st quarter last

fall we said that your weight was dependent on the distance

from the earth's center that you are standing. Therefore

you would weigh more at the beach at Rocky Point then you

would on Mt. Lemon. But your mass would be the same.

Objectives:

1.- You will be able to state from memory Newton'sthree laws of motion with no mistakes.

2. You will be able to distinguish between speed andvelocity.

3. Given the mass of an object and its accelerationyou will be able to calculate the force exertedbetween two bodies.


1. Read pages 92-102 in Modern Science 3.

2. Work out and hand in he 5 review questions onp. 102 in Modern Science 3.

. Instructor lectures.

4

Activities:

1. Work out the following problers. Show all your work.

A. If a 100 kilogram paratrooper accelerates 9.8n. sectas he falls frm the airplane, what is the fote ofattraction bqtween the paratrooper and the earth?(h:nt, F -=. m`i e

B. If a 30 kilogram bail is druped from a tower and hasan acceleration of 9.8m/sec4, what is the force ofattraction between the ball and the earth.

Quest:

Work out and hand in the following problem showing allyour work.

What is the velocity of a .25 kilogram baseball if thepitcher exerts a force of 25 newtons during a .5 second throwbefor*gb it is released?

(hint see page 101 in Modern Science 3.)

. Post-Evaluation:

1. State from memory Newton's three laws of Motion withno mistakes.

2. distinguish between speed and velocity by writing adefinition for each term with no mistakes.

3. Hand in problems IA and lB from the Activities sectionfor grading.

4. Hand it your review questions from p: 102 in ModernScience 3 for grading.

6

Problem 3

Mechanics - Calculation of Ideal Mechanical Advantage (IMA)

Rationale:

Most machines are designed to give us some advantage,

however some are simply to change the direction of the applied

force. In this problem ydil will learn how to calculate the

Ideal Mechanical Advantage (IMA)of some simple machines. When

figuring IMA we do not consider any energy lost to friction.

Objectives:

1. You will be able to calculate the Ideal MechanicalAdvantage LIMA) of some simple machines.


1. Modern Science 3 p. 105-106

2. Patterns and Processes of Science p. 263

3. Instructor lectures

7

Activities:

1. Work the following problems, showing all work:

A. If; R = 5g

E = 10q

Ed= 2 cm

Rd = 4 cm

Then; IMA =

B. If; R = 3g

Rd = 4 cm

E = 6g

Ed

= 1 cm

Then; IMF, =

C. If; R = lOg

Rd = 7 cm

E u 35 g

Ed = 4 cm

Then; IMA =

D. If; R = 3g

Rd = 7 cm

E 7g

Ed = 1 cm

Then; IMA

H. How much effort would it take to roll a 9 pound barrel

Activities (cont'd)

I. By applying an effort of 10 grams at the end of the

rope in this pulley arrangement how large a mass could

you lift?

Cal cul af...e. -fie I NI P

10

Post-Evaluation:

Obtain from instructor.

Quest:

Calculate the IMA for the following machine.

IMA for lever A

IMA for pulleys

IMA for lever B

total IMA

R

trn

fu

grams

11 iBq.

"4-9.04A-1e ID

Problem 4

Mechanics - Vectors

Rationale:

Forces have direction. A vector is a quantity which

has direction. Velocity, acceleration and force are all

vectors. Often two or more forces are applied to an ob-

ject at the same time. Often at is necessary to know

what the total force is and in what direction it is applied.

Objectives:

1. You will be able to determine the force and directionof the resultant of 2 forces acting on a body by agraphical method.

information Sources:

1. Read pages 102-103 in Modern Science 3

2. Work and hand in review question 1, 2, & 3 on page 105in Modern Science 3.

3. Instructor lectures.

Activities:

1. Complete and hand in Sheetfil."How do two forces affect

a body's motion".

Post-Evaluation:

1. Hand in review questions 1,2 & 3 on page 105 in Modern

Science 3 for grading.

2. Hand in Sheet PWLfor grading.

12

.2he following material has been deleted: How Do Two Forces AffectA Body's Motion?

Problem 5

Mechanics - 1st Class levers

Rationale:

When you were just a kid tyou are now a young adult)

you played on a see-saw or teetor-board, or whatever you

called it. If you wanted to play with someone smaller than

yourself you moved toward the middle of the board so you

would balance better. Did you know that you were operating

a simple machine, a 1st class lever?

e-5i5-t2tice- (----Ed -- fort

Rd lafar IA.J11....

Objectives:

1. You will he able to calculate the IMA of a 1st class leverand list at least 5 examples of a 1st class lever.

2. Given a resistance and applied effort you will be able todesign and build a 1st class lever that would do the job.


1. Read page 106 in Modern Science 3


3. Read pages 261-262 in Patterns and Processes of Science

13

0

Activities:

1. Work out and hand in sheet M-2 "How do Machines IncreaseForce".

2. There is a mass of 500 grams that you must lift and youonly have 50 grams of effort that you can apply. Designa 1st class lever to do the 3ob, calculate the IMA andshow your design to your instructor. After yout designhas been checked obtain the necessary materials and buildyour machine and see if it does work. Have the instructorcheck your machine.

Post-Evaluation:

1. Hand in Sheet M-2 for grading.

2. You will be graded on the machine you built in Activity 2.

3. List from memory 5 examples of a 1st class lever.

14

4

The following material has been deleted: Aow Do Machines InzreaaeA Force I (Levers, Wheels and Axles)

:lecnan17:s ,ss

icdtiQ _

a 2nd lever

Lance sets between

Obiectives:

_ever the rsasis-

1. You wtli e able tc t7,e c,lass

lever and give at 'east = 7,-.f a 2ed c.ass lever.

2. Given a Iesistanee c=.--.111,t:. e:f7z1 1,,11 he ableto design and build 2n class lever to d: toe ;ob.

3. You will be able to i _st the 7 or.lportr.ntie andreciu7_rements for a ca.:e_r in the field ot transportation.

Infcrrnat.on Sources:

1. Read page 108in Modern Science 3

2. Read pages 261-2:J2 in Patterns & Processes or Science


Activities:

1. Solve the foil blems; show

Activrtie cc.ntinuf7:d

A. E = 5c

El = 3m

R - 10g

Rd

IMA ---

B. E ---

Ed = 10 cm

R = 100 g

Rd = 20 cm

IMA = 2

C. E = 15 g

Ed

=

R = 45 g

Rd 50 cm

IMA = 3

2. There is a mass of 500 grams that you must lift andyou have 100 grams of effort that you can apply. Designa 2nd class lever to do the job, calculate the VIA andshow your design to your instructor. Nfter your designhas been checked by the instructor oltain the rlcessarymaterials and build your machine. Have the instructorcheck your machine.

Go to the library and list th,. ;3b opportunities andrequirements for a career in the field of transportation.

16

Post-Evaluation:

1. Have your problems checked by your instructor

2. You will be graded on the machine you built in Activity 2

3. List from memory 5 examples of a 2nd class lever.

4. Hand in your career report:

17

Problem 7

Mechanics - 3rd Class levers

Rationale:

A 3rd class lever has a different purpose than the

previous two. It has a speed advantage rather than a force

advantage. The effort applied will always be greater than

the resistance but a small movement by the effort will cause

a larger movement by the resistance. Your forearm is a good

example-of a 3rd class lever.

0,47_cat_4, 1DIA k rum

kesisfance, /ed. "*.

Objectives:

1. You will be able to list from memory 5 examples of a 3rdclass lever.

2. Given a resistance and applied effort you will be ableto design and build a 3rd class lever to do the job.

*Information Sources:


2. Read page 262 in Patterns and Processes of Science


Activities:

1. You have a 500 gram resistance that you wish to move andhave 1000 grams of effort to apply. Design a 3rd classlever to do 4'..e job, and calculate how far the resistancewill move if the effort force moves 2 cm. Have your designchecked by your instructor and then obtain the necessarymaterials and build your machine. Have your instructorcheek your machine.

18

Post-Evaluation:

1. List from memory at least 5 examples of a 3rd class lever.

19

Problem 8

Mechanics - Pulleys

Rationale:

A pulley is a modified lever. A fixed pulle., works

like a first class lever. The pulley axle is the fulcrum

and the effort and resistance firms are equals. Therefore

there is no force gain (IMA = 1) when us ing a single fixed

Rd - resistancedistance

Ed = effort distance

les15+anct

Rd d d

therefore IMA = 1

If the pulley is attached to the resistance (R) and one

end of the rope is fixed then the pulley is equivalent to a

second class lever.

(see -p'IcAukRe or WeAkt,

20

Res'iSio.r,,c,e,

Objectives:

cQ., Rd a E4

"thfiAAtellJL, 1MA= a.,

1. Given any pulley system, you will be able to calculatethe IMA of a pulley system.

2. Given a resistance and an applied effort you will beable to design and build a pulley system to do the job.




21

Activities:

I. Complete and hand i,. Sheet M-3.

2. There is a mass of 1000 grams that you must lift with anapplied effort 250 grams. Design a pulley system to dothe job, calculate the IMA and show your design to yourinstructor. After your design has been checked obtain

.the necessary materials and construct your machine andsee if it works. Have the instructor check the machine.

Post-Evaluation:

1. Hand in sheet M -3 for grading

2. You will be graded on the machine you build in Activity 2

22

The following material has been deleted: How Do Machines IncreaseA Force II (Pulleys and Gears).

Problem 9

Mechanics - Inclined Plane

Rationale:

Th-2 simplest machine known to man is the inclined plane.

It has not moving parts and was the basis for man's first tools.

The hatchet, wedge, shovel and plow are all examples of the

inclined plane.

Objectives:

1. You will be able to calculate the IMA of any inclinedplane.

2. Given a resistance and and an applied effort you willbe able to design and construct an inclined plane todo the job.



2.- Instructor lectures

Activities:

1. Complete and hand in Sheet M-4.

2. You have a toy truck with a mass of 1000 grams that mustbe lifted a height of 10 cm but you only have an appliedforce of 300 grams to move it with. Design an inclinedplane to do the job. Calculate the IMA and have yourdesign checked by your instructor. After your designhas been checked obtain the necessary materials and con-struct your machine. Have your instructor check yourmachine.

Post-Evaluation:

1. Hand in Sheet M-4 for grading.

2. You will be graded on the machine you build in Activity 2

23

The following material has been deleted: How Do Machines IncreaseA Force III (Inclined Planes and Screws)

SAHUARITA HIGH SCHOOL

CAREER

CURRICULUM

PROJECT

COURSE TITLE: GENERAL SCIENCE

PACKAGE TITLE: ELECTRICITY

BY

LARRY CHRISTENSEN & ROBERT LANE

General Science

Electricity

Unit IVPretest

Select the term that best completes each of the foiiowingstatements. Place tne letter of the best term in the blankbefore the correct question.

1. The original voltaic battery was made from (A) apenny it a lemon (B) zinc and copper discs (C) car=bon and zanc rods (D) lead plates in acid

2. The scientist w.h proposed that the existence - of"animal electricity" was demonstrated when a trog'sleg touched two different metals Is (A) Volta(B) Galvani kC) Faraday kD) Becquerel

3. If a rubber rod is rubbed vigorously, it is (A) chargednegatively (B) charged positively kC) discharged(D) uncharged

4. High-voltage current sent over power lines is changedto 110 volts out51,4q i^-'r house by a (A) generator(B) motor (C) step-up transformer (D) step-downtransformer

5. The electromotive force that pushes electricity througha wire must overcome (A) current (B) resistance(C) voltage (D) amperage

6. A single coil rotating in the field of a horseshoemagnet produces (A) alternating current (B) inducedcurrent (C) high resistance (D) high voltage

7. When we "charge" a storage battery we reverse theprocess of changing (A) chemical energy into elec-tricity (B) electricity into chemical energy (C)

mechanical energy into electricity (D) electricityinto mechanical energy

9. The Law of Magnetism states that (A) like poles repel(B) unlike poles repel (C) like charges attract(D) unlike charges attract

9. Ohm's Law states thatElectromotive force

(A) Current = Resistance (C) Resistan

Resistance(B) Electromotive force - Current

Resistance(D) Current = Ear Mrce

-"-nntElectr0-

10. A group of eiectriceceii6 =0,7,M6 -A an c.actrode(B) an electrolyte \(C) a trinto:mer (Di battery

11. A magnetized needle suspendid in a coil ut ire

makes a simple (A) galvanometer (D) motor

(C) electromagnet (D) electroscope

12, If a negatively charged rod attracts an object, theobject must be crarged (A) negatively (B) positively(C) positively or be uncharged (D) negatively or be

uncharged

13. Scientists measure current in (A) electrostatic forces(B) ohms (C) volts (D) amperes

14. In an electric motor, the device that reverses thecurrent in the rotating coil at the correct instant is

the (A) armature (B) cathode (C) commutator (D)gal-

vanometer

15. If you place your left hand near an electromagnet, withyour fingers bending around the coil in the directionof electron flow, your thumb will point to the (A) North

pole of the electromagnet (B) South pole of the elec-tromagnet (C) source of electricity (D) center of the

electromagnet.

After you have completed this Pretest bring it to the Quiz-

master for checking right_away.

2

General Science

ELECTRICITY

Unit IVProblem 1

Objective 1 - Demonstrate in five ways how electrons reactwith other electrons, atoms, ions and molecules.

RATIONALE:

The Van de Graff generator Is a device to easily removeelectrons from the outer orbits of molecules. _For example,if you comb your hair with an insulator (called a comb) youactually scrape electrons off the molecules of your hair. Aninsulator is a material t--lat conducts electrons very poorlyso the electrons stay on the insulator.

If it is dry, the comb is an insulator. The comb nowhas an excess of number of electrons. We say it is negativelycharged.

Your hair ts now positive (since there is a greater numberof protons and it needs electrons. In a few minutes it willgain electrons from your body or the air.

Sources of Information

Filmstrip:Book:finistrip:Book:Book:

"Static Electricity"The Physical World, read pages 236-239Life "Earth's Magnetism"The:Physical World, pages 248, 244-247Modern Science 3, pages 253, 239-244

ACTIVITY 1

Tear a sheet of paper into small (1 mm x 1 mm) pieces.

These bits of paper will be neutral electrically sincetheir protons and electrons are balanced.

Take your comb and comb v,,ur hair several times, causingthe comb to become negatively charged.

Bring the comb close to the paper. What happened?

Unit 10Problem 1

If the bits of paper were neutral (no charge electrically),why should they have been attracted to the comb? Study_thediagram below and write a brief paragraph to explain what youthink might have happened.

paperCO excess of electrons

Check with the instructor before going further.

ACTIVITY II

Slow up a balloon. Rub it vigorously on your clothing orhair. Put in on the wall. What happened?

Fill in the positive and negative charges in the diagram belowand write a brief explanation of what you think happened.

iloon

Check with instructor before goingon.

4

ACTIVITY III:

Unit IVProblem i

To make it easier tc scrape electrons oft, a V,..n deCraff Generator is used Ask your instructor to -.low itto you.

As the belt keeps moving, the hollow ball will buildup a strong positive cnarcie as electrons are moved from theball.

powesourc

electrons move down the belt

electrons are picked off byneedle to ground

With the large ball needing electrons, any object broughtnear the ball will tend to lose electrons to the ball. If youget too close arc will occur. If you measure the spark (arc),the voltage developed is about 30 kv (30,000 volts) per centi-meter. DO NOT BE AFRAID. IT IS NOT DANGEROUS.

Turn the generator on. After you run it for about oneminute, put your finger up to it. Measure the spark. Howmany centimeters?How many volts did you get?

ACTIVITY IV: (Check your answer with your instructor)

Hold a plastic ball on.W string above the generatorterminal. (the ball at the top of the generator is its terminal)

What will the plastic ball lose to the sphere when it touchesit?

Can you explain why the plastic ball is repelled by the sphereafter it touches it?

5

Unit IVProblem 1

ACTIVITY V:

Take two balloons that have been blown up and tie themto 50 cm of string.

Bring only one balloon to the sphere to be charged. Itis now a Bring it to the other balloon.What happened and why?

ACTIVITY VI:

Now charge up both of the baloons on the sphere one at atime. Try to bring them together. What happened and why?

Check your work with your instructor before going any fur-ther.

ACTIVITY VII:

Charge a plastic coat hanger or rod or test tube by rut-IIingit lightly on the sphere. Turn on your water faucet slowly.Bring the plastic hanger or rod near the stream of water. Whathappened and why?

6

Unit IVProblem 1

What you have been working with up to now in Problem 1 isstatic electricity. This means stationary charges of eitherelectrons, or positive ions or negative ions.

When electrons are moved along a conductor, like waterthrough a pipe, we cell this current electricity.

Check with the quiz-master about what you know.

7

General Science

RATIONALE:

Unit IVProblem 2

ELECTRICITY

Objective 1 - Demonstrate how to use a galvanometer.

Objective 2 - Stute a rule for the streIlth of mag-netic field around a coil.

Objective 3 = Demonstrate the voltaic pile.

To understand how electrons move in a conductor we wishto use an analogy with water.

Pretend you have a rubber hose wrapped seven times aroundthe equator of the earth. Preten the hose is full of water.You have a pump on the end of the hose.

When you push down on the handle of the pump, the watersquirts out of the other and of the hose in one second. Noticethat all the water did not move to the other end. You pushedwater in nne end and therefore the water was squirted out theother en(

If you pushed down on the handle, and one second later,the water squirted from the other end--it means the water,186,000 miles from the handle, was the water that squirtedout. (Figure the hose is seven times around the equator whichii-approximately 186,000 miles of hose).

Tn effect it is as if the impulse that caused the waterto spirt ou122£eid4asltravell1M,000miwhich is spee of ig t.

Now, the same thing occurs in an aluminum or copper wire.If the wire is hooked up to a bat.ery and the circuit closed,electrons :ove into one end of the wire. They push the nextelectrons, which in turn push the next, etc. These electronsthat are being pushed are in the outer shells of the atoms ofthe wire. They are the least affected by the nucleus.

The electrons that move into one end of the wire causeelectrons to move out the other end of the wire. At E speedof 186,000 miles per second, the electrons will be pushed outthe other end of the wire.

Unit IVProblem 2

This, then, is called current electricity---where elec-trons move along a conductor. The best conductors are silver,copper, and aluminum because their out shell of electrons areat energy levels which are easy to dislodge.

Sources of Information:

Filmstrip:Book:Pilastrip:Book:Book:

ACTIVITY I:

"Static Electricity"The Physical World, read pages 236-239Life "Earth's Magnetism"The Physical World, read pages 248, 244-247Modern :.fence 3, nages 253, 239-244

Obtain a flash' ght battery, 2 wires, and a miniaturelight in it' receptacle. Show that you know the proper con-tacts to make the light glow.

Draw a diagram of your apparatus when finished below.

CHECK WITH YOUR INSTRUCTOR WHEN FINISHED.

ACTIVITY II:

From your instructor ob'ain a device to detect electronflow. This is called a galvanometer. It can be made by wrap-ping several turns of wire around a compass as in the diagrambelow.

wire SimpleGalvanometer

Unit IvProblem 2

Line up the wires of the coil so they point to themagnetic north. This is important. (Magnetic north is 13°to the right of true geographic north in Tucsonl

Now record how muchdeflection of theneedle you get indegrees, when youuse a flashlightbattery.

Magnetic north is 13° tothe right of geographicNorth in Tucson.

degrees

Now reverse the wire onthe battery. What hap-pened?

What were the degrees ofdeflection?

degrees

THE DEFLECTION OF THE COMPASS NEEDLE GIVES THE DIRECTION OFTHE MAGNETIC FIELD.

A flashlight battery is a dry cell. It is 1 1/2 volts andgenerally produces from 3 to 5 amperes of current. Look upthese new terms in the text books in the reference sectionof the room and briefly write their meanings.

1-dry cell

2-volts

3-amperes

CHECK WITH YOUR INSTRUCTOR BEFORE GOING ON.

10

N

Unit IVProblem 2

ACTIVITY III:

Every conductor through which electrons are flowing issurrounded by a ma netic field.

N

battery

S

Magnetic field

This discovery was made by a Danish scientist Hans Oerstedin 1819. TWO, years later, a Frerlh scientist Andre Ampere founda coil of wire carrying an electric current acted the same wayas a magnet, that is, it had north and south poles.

In Activity II, the magnetic field produced in the coilaround the compass tended to deflect the needle. ribe morethe turns of wire of -the coil, the stronger the magnetrarieldwill be. The stronger the current, the stronger the magneticfield will be.

S

Using the above information, briefly explain each of the diagramsbelow.

A

iron filings

B

N

411

,40064vIron filings

Why did the iron filings drop in diagram B?

11

Unit IVProblem 2

2- When I connect the ends of the two wires in each of thediagrams below the needle -f }he compass will move. In eachcase draw in the direction the needle will deflect to.(Remember: The North pole of a magnet always points in thedirection of the magnetic lines of force at that place).

ACTIVITY IV:

In this activity you are to make Aleasandro Volta's originalbattery, which he made in about 1800.

1-Cut up a paper towel into approximately 4 centimeter squares.2-Stick the squares in salt water (saturate them but they shouldnot be dripping)3-Obtain or cut up with tin shears, 10 zinc 'Ind 10 copper squares.They should be about 4 centimeters square.4-Alternate your copper and zinc pieces (they must be clean andshiny-use steel wool if necessary.)5-Place about 5 paper towel squares between each metal piece.

Cu

an EMSE0 \stowel +salt water

cu ======-moms

Zn =cm

galvanometer

6-Attach the wires from your simple galvanometer to the topand bottom of your pile.7-What happened?8-Show your Voltaic Pile to your instructor.

12

Unit IVProblem 2

ACTIVITY V:

The voltaic cell which ycu made was first proposed byAlessandro Volta. an Italian physicist. It involved theuse of chemical energy to change two rods with electricityof opposite sign.

Think back to the experiment in which you added zinc tohydrochloric acid. What gas was formed?The zinc became negatively charged. This happened becausethe zinc atoms that combine with the chlorine , and then floatin the solution (the black specks you saw), leave the twoelectrons from their outs: shell behind on the main piece ofzinc. Therefore, this main piece of zinc has more electronsthan it needs, and it has a negative charge.

The chemical salt solution does the same thing. Therefore,the zinc square in your voltaic pile has a charge.

When the hydrochloric acid bonds break, the hydrogen isleft with too few electrons. It needs electrons and if thereis another metal, such as copper present, it will take elec-trons from the outer shell of the copper atoms. This leavesthe copper atoms with too few electrons and they are now posi-tive ions.

. The chemical salt solution does the same thing. There-fore the copper squares in your voltaic pile have acharge.

Now we have negative and positive charges. We have learnedin our investigation that the charges move towards the

charges.

Notice that we have changed chemical energy (salt, solution,copper, zinc) into electrical energy (positive and negativecharges).

The substance producing the electrical charge are calledELECTRODES. The copper is the positive electrode and the zincis the electrode. The positive electrode isknown ai-INi ANODE. The negative electrode is known as theCATHODE.

Zinc is the electrode and is known as the

Copper is the electrode and is known as the

13

Unit IVProblem 2

The chemical solution which acts on the electrodes iscalled the ELECTROLITE. The L.alt solution is theSince it is a liquid, this kind of voltaic cell is called aWET CELL. Each WET CELL is composed of one square of zincand one square of copper separated by paper towel soaked insalt solution. - -

zn

cu

VoltaicCell

zn

cu

zn

cu

VoltaicBattery

When you make a voltic-pile, you are using several wetcells stacked together. This is a simple BATTERY. A batteryis composed of two or more cells.

CHECK WITH YOUR INSTRUCTOR BEFORE GOING ON.

Activity VI:

Obtain problem sheet El. 3 frenn the file and perform theexperiments as stated. Be sure to take notes and state yourresults in your notebook.

14

General Science

Electricity

Unit IVProblem 3

Objective 1-Demonstrate the measurement of electricalpotential (voltage) of various objects witha voltemeter.

OVERVIEW:

You have now seen how electrical current may be producedby chemical as well as magnetic and mechanical means. We willnot study the actual generation of large amounts of currentunless you care to do an added study, but we need to be ableto measure potentials and amount of current in order to useit wisely and be able to protect ourselves from electricity.

-Electrical potential (voltage) actually is a measure ofthe electromotive force_(EMF) pustng electrons from one place

uto another. Since the units used in electricity may all benew to you I will state the relationship between coulombsand volts. *Remember that the coulomb was 6.25 x 1018 elec-trons passing a given point in one second. A volt of elec-trical pressure is present when one joule of work will movea coulomb of charge between two points. or

1 volt = 1 joule1 coulomb

One flashlight cell produces 1 1/2 volts. Two flashlightcells (battery) should produce 2 times as much voltage whichwould be 3.0 volts - this is the amount of emf or electricalpressure between the posts of the cells.

The voltmeter measures emf between two points in a cir-cuit. Actually the voltmeter measures the difference inelectromotive force between the two points where it is con-nected in a circuit. It is this difference in emf or elec-trical pressure that causes a current to flow through a wire.The flow isfrom the area of greatest potential to that oflesser potential.

Why would you not plug a toaster that had 115 voltsprinted on it into a supply that had 220 volts?

ACTIVITY I:

Obtain problem sheet E 1.5 and read it carefully.

ACTIVITY II:After asking the instructor any questions you might have

about E1.5, perform the indicated procedure and note any obser-vations and results in the proper place.

ACTIVITY III:After you have practiced measuring the voltage of several

sources cheek with the quiz-master about a demonstration of yourskill. Be sure to have your orf,h1=m sheet completed.

15

General Science

Electricity

Unit IVProblem 4

Objective - Demonstrate the measurement of current (amperage)in an electrical circuit with an ammeter.

OVERVIEW:

You have just ccmoleted a measurement of the pressure(force) causing charges to flow. -If there is enough pressure

-to cause a current then we can determine the current flow withanother instrument called an ammeter. The voltmeter is a highresistance in order not to affect the actual flow but only tomeasure it. A voltmeter was connected in parallel to the cir-cuit but the ammeter is connected in series.

In electricity the greater the number electricalcharges flowing'per second the "stronger:: the current. Onecoulomb of electric charge is 6.25 x 10 electrons or625,000,000,000,000,000,000.

1 ampere = 1 coulomb1 second_

For example of how this applies see the following:A steady current flows through an electric lamp for a

period of 5 seconds. During that time, 15 coulombs of chargepass a reference point in the filament of the lamp. What isthe strength of the current during the 5 second period? Didyou answer 3 amperes? Good! If not, see how we arrived atthat answer.

15 coulombsCurrent (amps) = 5 seconds = 3 amps

In practice one does not ston to think how many electronsare passing when one is measuring the current so lets look atthe actual current measurement.

ACTIVITY I:

Obtain Problem Sheet E 1.E from the file and read itcarefully. Ask the instructor any questions you might haveabout the problem or explanation.

ACTIVITY II:

After checking any questions with the instructor obtain010 necess ry materials from the aide and set up the apparatusas pictured.

16

Unit IVProblem 4

ACTIVITY III:

Perform the procedures outlined and note your oherlr-vations and results in the notebook. Check with the quiz-master before taking down the apparatus.

When you are competent in making current measurementscheck with the quiz-master with your problem sheet.

ACTIVITY IV: (OPTIONAL)

Obtain problem sheet E 1.7 from the file and follow thedirections carefully. Complete any problem calculations andbring the completed problem to the quiz-master for credit.

17

General Science

Electricity

Unit IVProblem 5

Objective 1-Explore skills and knowledge that are usefulat home in working with electricity.

Objective 2-Explore sc.:me occupations in which electricalknowledge is necessary.

OVERVIEW:

What is a fuse for? What happens when a penny is placed

behind a fuse? How do I read an electric meter? Why can't

I plug in the toaster, the TV, the tights, and the stove all

on the same 30 amp circuit and have them all on? Some of the

answers to these questic,,q may be obviour to you but to many

people they are not. In the problems of_, this unit you have

no doubt answered some of these but in the optional problemsyou might find more answers if you are interested.

What are some of the jabs that require electrical know-

ledge: The obvious ones are construction wiring for lights

and appliances, linesman opportunities, appliance repair,

motor repair and wiring, electricians for general work, and

electrical engineering. General knowledge of electricity maylead to opportunities in electronics also which appears to bean important field in the next 20 years.

What training or skills do you need for occupations in

electrical fields? First you generally need a high schooldiploma with general knowledge of math and science. It is

important that you have manual dexterity and for constructionand linesman's jobs you must be in good health. What do you

like? Outdoor' tork or nice cool indoor work? Don't over)--''

the opportunities of getting your training in the service,fellows, as this also allows you to get that obligation out

of the way. By the way, girls, there is a growing number of

women in assembly and repair departments of electrical compan-ies because they are generally handier with small electrical

materials.

Let's look further for more facts and more ideas about

these occupations.

Do activities l'IV for minimum credit and activity V for

added credit.

18

unit IVProbler 5

ACTIVITY I:

Obtain problem sheet E 1.14 from the file and read itcarefully.

ACTIVITY II:

Obtain the, necessary material from the aid and performthe simple experiments outlined.

ACTIVITY III:

Write the procedure and observations in your notebookalong with answers to the exercises listed in the problem.

ACTIVITY IV:

Check the occupations file in the library about jobsdealing with electricity Make a list of at least 10 jobsdealing with electricity in your notebook.

ACTIVITY V:

Conduct an interview with some one that works in somefield related to electricity such as an electrician, arepairman, an auto mechanic, a lineman, or a radio operator.Discuss this interview with the quiz-master.

19

General Science

Objective

Objective

OVERVIEW:

Unit IVProblem 6

Electricity

1-State Ohm's Law and discuss applications inyour home and school.

2-Sta4-_e the uses of series and parallel circuitsand demonstrate the proper connections for eachtype circuit.

You have already mad. measurements of voltage and amperageand you no dr-°-* found that different lengths of connectingcords caused different amounts of current. Ohm's Law statesa connection between the three factors which affect a givenflow of current. Stated:

current (amp) = resistance (ohms)

or in symbols: I = RV

potential (volts).

This relationship can be manipulated like any algebraicformula to find any of the three factors; given the other two.Remember that volts is a measure of electromotive force and Eis often used inste, <= of V.

In setting up various circuits it is important to knowwhat power requirements you will need and what kind of resis-tance will be used in order to know how many devices (appliances)you can add. Since most 'ircuits need some control it is impor-tant to know what effect series or parallel connections haveon a circuit. For example: a fuse would not be effective ifhooked in a parallel and likewise if your toaster and ironwere hooked in a series circuit they would both have to beon for either one to work and that would be costly.

Let's see how it works by doing some experiments.

ACTIVITY I:

Obtain problem sheet E 1.8 and read it carefully. Ask theinstructor about any items which are not clear to you.

ACTIVITY II:

After checking with the instructor, obtain the necessarymaterials from the aide and perform the experiments outlined.

20

Unit IVProblem 6

ACTIVITY III:

Write a brief statement in your notebook about Ohm's Lawand work the exercises in problem E 1.8. Make any observationsand results a part of your notebook work.

ACTIVITY IV:

Obtain problem sheet E 1.9 from the file and rePL it care-'111v. Ask the instructor about any items which ar not clearto you.

ACTIVITY V:

Obtain the necessary materials fr A the aide and set upthe apparatus as outlined and pictur u. Perform the experi-ments listed and be sure you pay r .3se attention to the voltagelisted.

ACTIVITY VI:

Answer the exercise questions on problem E 1.9 in yournotebook and also note any observations.and results from theexperiments.

Bring your notebook to th. quiz-master when you are readyfor an evaluation of the objectives stated. Be sure vou knowwhen and why series or parallel circuits are used.

21

SAHUAQITA HIGH SCHOOL

CAREER

CURRICULUM

PROJECT

44,


PACKAGE TITLE: PHYSICAL SCIENCE IN GENERAL SCIENCE

BY-.1.....v .


CONTENTS

Ae Mechanics

B. Electricity

C, Light

Physical Science

Introduction to the Quarter

In the physical world, man's climb from the primitive

has always depended upon the use of power. In the beginning

it was muscle power, then animal power, and now electrical

and chemical power. The total power available has multi-

plied hundreds of thousands of times in just the last 100

years. In this quarter you will investigate some of the

physic,i features of basic machines, electricity, and light.

2

Objectives

1. Transportation Cluster

2. Specific Career Gojectives

A. Auto MechanicB. ElectricianC. PhotographyD. Civil EngineerE. Airplane PilotF. Ship's CaptainG. Aerospace TechnicianH. Aircraft Mechanic

36, Objectives

1. You will be able to define from memory 9 of10 of the following terms: fulcrum, idealmechanical advantage, force, a newton (nt),work, rector, friction, lever, pulley, in-clined plane.

You will be able to state from memory Newton'sthree laws of motion with no mistakes.

3. You will be able to distinguish between speedand Velocity.

4. Given the mass of an object and its acceleration,you will be able to calculate the force exertedbetween two bodies.

5. You will be able to calculate the ideal mechani-cal Advantage (IMA) of some simple machines.

6. You will be able to determine the force anddirection of the resultant of 2 forces actingon a body by a graphical method.

7. You will be able calculate the IMA of a1st Class lever and list at least 5 examplesof a 1st class lever.

8. Given a resistance and applied effort you willbe able.to design and build a 1st class leverthat would do the job.

9. You will be able to calculate the IMA of a 2ndclass lever and give at least 5. examples of a2nd class lever.

JO. Giv:-% a rus2S t.anc,7. and apn_ied effort you willbe coif' a 2nd class leverto Cl.; t,.e lob.

You will be ab4.e to list the job opportunitiesan:; requIrements for a career in the field oftrinsputatlon.

12 You will be ablc, to list from memory 5 examplesof a 3rd class lever.

13. Given a resistance and applied effort you willbe abic tc design and build a 3rd class leverto do tne :ob

14. Given any pulley system, you-will be able tocalculate the IMA of a pulley system.

15. Given a resistance and an applied effort youwili be able to design and build a pulley sys-tem to do the job.

16. You will be able to calculate the IMA of anyInclined plane.

17. Given a resistance and an applied effort youwill be able to design and construct an .1.nclinedplane to do the job.

18. Demonstrate in five ways how electrons reactwith other electrons, atoms, ions and molecules.

19. Demonstrate how to use a galvanometer.

20. State a rule for the strength of magnetic fieldaround a coil.

21. Demonstrate the voltaic pile.

22. Demonstrate the measurement of electrical po-tential (voltage) of var±-.Jus objects with avoltemeter.

23. Demonstrate the measurement of current (amperage)In an electrical circuit with an ammeter.

24. Explore skills and knowledge that are usefulat home in working with electricity.

25. Explore some occupations in which electricalknowledge is necessary.

26. State Ohm's Law and discuss applications in yourhome and school.

4

2i. State th2 uses of _;cri.cs narallr-1 circults and 'emonstrale the proper connectionsfor each Lyre clict.

28. identity w!at is and deterrilfle sveraiways it ma-:- he produced.

29. Identity or demonstrate certain properties ofllont such 11,..:;mnati3n, travel, and inten-sity.

30. Demonstrate light travel, illumination, andimage PN' use if a pin-hole camera.

31. De-riGn5:-tra-_ -_nat light travels in a straight

32. Identity units sicri as .:andles, lumen, andinverse proportion.

33. Demonstrate .a standard measure of illuminationby actual experimentation.

34. Demonstrate what hapnens when light hits vari-ous types of surfaces.

35. Define .nd demonstrate the "Law of Mirrors."

36. Demonstrate what happens to light when itpasses thru various interfates such as water-air, air-glass, and glass-air.

37. Identify the index of refraction for varioussubstances such as glass; ice, diamond, andwater and describe what this index might beused for.

38. To identify various uses of light, 1'nses, andmirrors for home, scientific, and industrialuses.

39. Identify the type of lens and demonstrate thearrangement of lenses used to form a microscope.

40. Identify the type of lens and demonstrate thearrangement of lenses used to form a refractingtelescope,

41. Identify the type of lens and demonstrate thearrangement of lenses used to form a lens systemfor a box camera as well as a common 35 mm lenssystem.

1

SAHUARITA HIGH SCHOOL

CAREER

CURRICULUM

PROJECT


PACKAGE TITLE: LIGHT

BY


General Science

Light

Unit VPretest

Answer each of the following questions as fully as possible.Use this sheet (back and front) and any otner blanks you needbut be sure to put the number of the question on any sheet.

1. What is light?

2. Explain what the law -f mirrors means; use diagrams tohelp explain.

3. How can white light be divided into the seven (six) dif-ferent colors of light?

4. What are the seven (six) colors of light that make upwhite light? List them in the order they are normallyseen in a rathbow.

5. What names are given to the two areas of invisible lightat each end of the visible spectrum?

6. If you wanted to see a baseball game, but a 7 foot boardfence was betwegn-you and the game; what are some meansyou could use to watch the game without climbing thefence?

7. Explain why the rays from an auto head light are directedout parallel frog, the reflector.

General Science

Objective

Objective

RATIONALE:

'snit VProblem 1

Light

1-Identify what light is and determine severalways it may be produced.

2-Identify cr demonstrate certain propertiesof light such as illumination, travel, andintensity.

For most of the scicatific age light has been consideredan energy due to the fact that its mass could not be measuredas "mase. It is now referred to as radiation and may bedetected by a human or electronic eye. Along with light wenormally associate heat energy but if at all possible forthis unit we would like to have you try to think only of thelight and not any accompanying heat. To explain light youmight pretend yoU are an "enlightened" earthling trying totell someone from a "dark" planet that has never seen light,what it is.

What do we know or can we demonstrate about light? Asfar as we will be concerned light 'travels in a straight lineuntil it meets some material object. Intensity of light Ismeasured at the source and is arbitrarily set in "candlfpower". The illumination varies according to the color ofthe source and thus a candle varies and it is not really thestandard now.

Illumination is actually more useful to us as this actuallysets up a standard as to how well lighted a subject is. Inten-sity and distance from be source are both considered in deter-mining illumination and the units used are: lumens - squaremeter or 1 footcandle which is the illumination one footTiEW-a standard candle. The foot-candle is the unit normallyused by lighting engineers and photographers to measure illumi-nation.

2

Unit VProblem 1

ACTIVITY I:

Read pp. 305-316 in The Physical World.

ACTIVITY II:

Take a candle from the tray and mount it on a squareof cardboard. Light the candle and study it briefly--writeyour observation in your notebook such as color, steadinessof flame and color, size and shape of flame, and any otherobservations that appear important.

ACTIVITY III:

Obtain a small flashlight bulb in a porcelain holdersuch as those used in elec"-ricitv and hook it up such that"light" is produced. Mak' observations about this sourceof light and write these in your notebook also. Do thestwo sources of light have anything in common? What? Explain.

ACTIVITY IV:

Obtain a problem sheet ol.l from the file and performthe activity listed. Answer any questions in your notebook.

Check with instructor before going further--bring yournotebook.

ACTIVITY V:

Read or reread pp. 315 and 316 in The Physical World.

ACTIVITY VI:

Obtain a problem sheet 01.3 from the file and performthe activities listed. Answer any questions in your notebook.

Check with the quiz-master and bring your notebook.Ask about alternate experiments if interested.

Filmstrip: SVE "Experiments With Types of Light"

3

General Science

Light

Unit ,11

Problem 2

Objective 1 - Demonstrate light travel, illumination, andimage by use of a pin-hole camera.

OVERVIEW:

Using the principle that light travels in a straightline until it meets some material object we can make a simplecamera from a box and a pinhole. Many good pictures havebeen made with pin hole cameras and if you have an interestin artistic pictures this is an excellent opportunity to tryyour luck. More complex cameras are very gimiliar in con-struction to a simple pin-hole camera; so lets.start at thebottom.

ACTIVITY I:

Obtain problem st.-.et 01.2 from the file and read itcarefully. You might need to discuss the chart on the backpage with the instructor or aide before you begin the actualproblem.

ACTIVITY II:

Obtain the needed material from the aide or the cabinetif you have permission.

ACTIVITY III:

Perform the suggestee, proceduretions and results in your notebook.

Check with the quiz-master about

QUEST:

and write your observa-

evaluation and credit.

If interested you might make ; -eal pin-hole box cameraand take pictures of various objects. The instructor willbe glad to advise and obtain a limited amount of film orpaper for you.

4

General Science Unit VProblem 3

Light

Objective 1 - Demonstrate that light travels in a straight line.

Objective 2 - Identify units such as ".andles, lumen, andinverse proportion."

Objective 3 - Demonstrate a standard measure of illuminationby actual experimentation.

ACTIVITY 1:

(It would probably beon this problem).

Read pages 463-473 inLook at experiment 7, pagesame book.

ACTIVITY II:

best for two people to work together

Patterns and Processes of Science.86 and experiment 9, page 111 in the

Identify the terms "candle, lumen, and inverse propor-tion" in your notebook and cheek with the instructor beforegoing further.

ACTIVITY III:

Reread experiment 43 beginning on page 467 and make surejou have a good idea of what you are going to demonstrate andow.

ACTIVITY IV:

Obtain the needed material and space from the instructoror aide and proceed:

ACTIVITY V:

Make all observations in your notebook along with thedata table and graph. If you need help with the graph askthe instructor or the math instructors. Use available graphpaper and staple this in your notebook or if you have a looseleaf just add on.

Check with the quiz-master when you have the equipmentset up and before you put everything away. Defend your graphfor a final evaluation on the problem.

General Science

Objective 1

Objective 2

Unit VProblem 4

Light

- Demonstrate what happens when light hits varioustypes of surfaces.

- Define and demonstrate the "Law of mirrors".

OVERVIEW:

Light travels in straight lines until it meets a materialobject; what happens then? What happens next depends upon thematerial object. If the material is transparent several thingscan happen such as the light bounces back reflection), bouncesoff at crazy angles (scattering), or passes through the objectbut is bent slightly (refraction). If the material is opaqueseveral things can happen but not refraction. If the materialis translucent all of the above can happen but a distinct imageis not formed.

Let's look at reflection more closely. The "Law of Mirrors"states that light is reflected so that the reflected and inci-dent rays make equal angles with the normal to the reflectingsurface. This law has been applied to flat mirrors or curvedones and should hold up for all.

ACTIVITY I:

Choose one of the sources of information below and useit accordingly. It might be a good idea to take notes onimportant points in your notebook.

Filmstrip:Filmstrip:Book.Book:

"Light and How it is Reflected""Experiments with the Reflection of Light"The Physical World read pages 270-274Modern Science 3 read pages 195-200

ACTIVITY II: (OPTIONAL)

Obtain problem sheet 01.7 from the file and read itcarefully. If interested in this, obtain the necessary mater-ials from the aide or the cabinet if You have permission.Perform the suggested activities and answer any questions inyour notebook.

Unit VProblem 4

ACTIVITY III:

Perform one of the two suggested problems below. Bothmay be done if you desire.

1. Obtain problem sheet 01.5 from the file and read itcarefully. Obtain the materials needed after askingany questions you might have about the set-up.After you have the material set up check with theinstructor before going further. After instructors'OK--perform any procedures outlined and write theobservations an;' results in your notebook. Checkwith the quiz-master for credit.

2. Read experiment 7, part B & C in Patterns and Processesof Science pages 86-89. If you choose this experimentmake a list of materials needed and an outline of theprocedure you plan to follow and have it checked bythe instructor. After the OK, obtain the neededmaterials and proceed. Be sure to measure carefullyand write your observations and results in your note-book. Check with the quiz-master before putting thematerials back and have him check your notebook forcredit.

Check with the instructor about a demonstration with thelaser on reflection.

7

General Science

Light

Unit VProblem 5

Objective 1 - Demonstrate what happens to light when itpasses thru various interfaces such as water-air, air-glass, and glass-air.

Objective 2 - Identify the index of refraction for varioussubstances such as glass, ice, diamon, , andwater and describe what this index might beused for.

OVERVIEW:

Refraction is that property of light that causes bend-ing of light as it passes from one medium to another. Thereare two types of explanations for this depending on whetherlight is a particle or a wave but we won't discuss that now.Refraction is a principle that is important in glasses,cameras, projectors, and almost any substance which man usesto alter the path of light.

Refraction can be important to a fisherman also to anoculist or an optometrist or even to an orthroptist. Whatis an orthroptist? In this problem you will be asked toanswer several questions about refraction and demonstratesimple observations about this.

ACTIVITY I:

Choose one or more of the sources of information belowand use it accordingly. It might be a good idea to takenotes on important points in your notebook.

Filmstrip:

Book:Book:

"Light and How it is Refracted""Experiments With the Refraction of Light'The_ Physical World read pages 275-280Modern Science 3 read pages 200-205

8

Unit VProblem 5

ACTIVITY II:

Choose one of the experiments listed below and followthe directions as listed.

1. Obtain problem sheet 01.8 from the file and readit carefully. Obtain the materials needed afterasking any questions you might have about the set-up. After you have the material set up check with-the instructor before going further. After instruc-tor's OK perform any procedures outlined and writethe observations and results in your notebook.Check wLth the qaiz-master about credit.

2. Read experiment 44 pages 478-481 in Patterns andProcesses of Scien..e. If you choose to do thisexperiment make a list of materials needed and anoutline of the procedure you plan to follow andhave it checked by the instructor. After beingOKed, obtain the-needed materials and proceed.

Be sure to use care in measuring and don't be afraidto ask question:. Work on neatness for your writtenobservations and results in your notebook. Check withthe uiz-master before taking down the equipment andhave him make a final check for credit.

Have you had any laser demonstrations yet? Axe youinterested in doing any experiments with it yourself?

General Science

Light

Unit VProblem 6

Objective - To identify various uses of light, lenses, andmirrors for home, scientific, and industrial use.

RATIONALE:

It is fairly obvious that Americans would be rather lostwithout light; and especially light from electricity. Someof you have no doubt used kerosene lanterns and also gasolinelanterns for camping or storm use but most homes in the U.S.now have a steadier form of light from electricity.

What d) you know about lighting for your reading or study?What do you know about glasses for reading? What do you knowabout lenses in a camera? What do you know about window glassfor a TB sanitarium? All of the above questions have to dowith occupations dealing with light. Your most common contactwith "Laws of Licht" ''ill no doubt be in using a camera, amicroscope, or a telescope (whether it be for hunting orastronomy).

Most jobs connected with lenses and light are technicaland all require a high school degree. The oculist grindslenses and the apprentice program for the lower level generallytakes two years or more. You need good manual and spatialdexterity to be an oculist plus a good background in mathe-matics so if that is one of your "impossible" areas this isout for you.

Photography makes an excellert hobby and if you have anyartistic ability or sense this hobby can be turned into aprofitable one. In fact you might even find it to be agood business for yourself.

Another good hobby is observation with a telescope.This hobby like photography can be expensive but if youlike to make things you can get started for less than $20.This "light laws" and hopefully will help you learn moreabout soe of the optical lenses about you. Why are goodlenses expensive?

Unit VProblem 6

ACTIVITY I:

Choose one or more of the sources of information listedbelow and use it accordingly.

Filmstrip: "Experiments with Color"Book; The Physical World, read pages 268-271

and 214-289

Book: Life Science Library - Light, read pgs. 70-90

ACTIVITY II:

Make a list in your notebook of at least two uses oflenses in the home, in the science lab, and in industry.(six uses altogether)

ACTIVITY III:

Write a few paragraphs about seeing in humans. How wecorrect faulty vision and how humans are able to see color.

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General Science

Light

Unit VProblem 7

Objective: Identify the type of lens and demonstrate thearrangement of lenses used to form a microscope.

OVERV1:17:

While the first microscope was little more than a magni-fying glass it was a big step for man to be able to polishand shape some glass to form a lens. Anton van Leuxwenhoek(1632 1723) is given credit for one of the earlist micro=scopes and as mentioned in problem 4 his skill at grindingand polishing was a hobby.

The historical development of the microscope is aninteresting-subject; and one that. reads some of the namesof early dbirelopers will recognize some names of presentexcellant lenses.

From the simple single lens scope to a compound scopethat might have three or more lenses to-one that uses electronenergy instead of light is quite a story but to appreciatesome of the early problems we would like to have you constructa simple magnifying glass-with a convex lens and-then useconvex lenses to form a compound microscope.

ACTTVITY I:

Read Sheet 34, Biology Resouces in Science ClassroomLibra . You might take some notes or make some microscopes etc es in your notebook riterest.-

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General Science

Light

Unit VProblem 8

Objective - Identify the type of lens and demonstre-e thearrangement of lenses used to form a refractingtelescope.

OVERVIEW:

Telescopes were assembled about the same time as theearly microscope's and Dutchmen were given credit for theearly experimental models. The skills developed by Dutch len'sgrinders made refractive lenses available and due to the timesmuch experimentation was taking place. Convex lenses were andare used in refracting telescopes and metal tubes connected thelenses. The early telescope was the type you normally see shipcaptains using to look over the sea.

The newer type optical telescopes are reflective hypes- that have a mirror for collecting light and then a camera orlens system to -refine the image. If you are interested in aspecial project on astronomy we now have an 8" reflectingscope which may be used for special project work. See theinstructor for further information.

ACTIVITY I:

Use, one or

Filmstrip:Sheet"

ACTIVITY II:

more of the references below:

"The Mount Wilson and Palomar Telescopes"Earth Sciences 9; "Optical TeIesco?es"read all pages and especially Gallileantelescope.

Identify the following terms in your notebook:

a. objective lensb. eyepieceC. comad. spherical aberration _

e. chromatic aberrationf. focal length

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General Science

Light

Unit VProblem 9

Objective - Identify the type of lens and demonstrate thearrangement of lenses used to form a lens systemfor a box camera as well as a common 35 mm lenssystem.

OVERVIEW:

As you found in the problem with the pin-hole camerayou can take pictures without a lens but for reliable andspeedy pictures in all lighting conditions it helps to havelenses. Prefocused lenses are common to all box cameras andgiven excellent snap-shots at given distances.

For greater variety of lighting and distance it isimportant to have a lens system that cuts out spherical endchromatic aberration and gives many adjustments for focusing.Photography can be an involves subject in itself so for nowlets look only at the lens system.

ACTIVITY I:

Read pages 291-297 in The Physical World and take needednotes in your notebook.

ACTIVITY II:

Identify the following terms in your notebook:

focal length, spherical aberration, chromatic aberration,fixed focus, objective lens, shutter, diaphrogm.

nit V L

ilace tte .f nr!St term in -ne blank nefore ,-f the ques-

tion ,151monts

An .,'c c`. ha' emits liRnt is said to be (a) luminous (h)

(c) c;.aque (d) transparent

2. trave1s in (a) a circular path (h) an ell.1-1,1 pathslraight Ifh,3 (d) straight or circular pathS

3. in a pinho2e ..:amera, the image formed on'the film (a) right

side un (h) reversed tc) inverted

4. The blocking of light produces (a) shadows (b) -.Tree".(s of light

(c) interference (d) dark and light lines

5. The lighter fringe of a shad,-;14 is called the (a) . _ r (b)

penumbra (c) polarized light (d) umbra

6. A liRht ray that strikes a reflecting surface i- :aid to be(a) a reflected ray (b) a normal ray (c) an absorbed ray (d)

an incident ray

7. Reflection from a rough surface is said to be (a) -1:ffuse(b) irreg-ular (c regular (d) translucent

8. Compared to the object, the image produced by the ot-Llect in

a plane mirror is (a) larger (L) smaller (c) the Fa-e size(6) cistorted

9. The da-. r inner part of a shadow is known as umnra

(b) crest Cr) penumbra (d) trough

10. The bending of light is known as (a) reflection (!-,) refraction

(c) diffraction (d) dispersion

11. A virtual image is seen when we use a -Ca.) microscope (b) movieprojector (c) magnifying glass (d) copying camera

12. A reflecting telescope consists of a convex lens, a plane mir-ror, and a_ (a) convex mirror (b) concave lens (c) magnifying-

Flas (d) concave mirror

. The band of colors of light, ranging from red to violet, iscalled a (a) rainbow (b) spectrum (c) diffraction crating

(d) pr sm.4

14. A transparent iect is the color of the light that the object

(a) transmits (b) reflects (c) absorbs (d) refracts

15. When an object reflects all light, i-t appears to be (.1) black

(1) red (.c) green (d) white

. II. Explain what the law of mirrors means; use diagrams to help explain.

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